Definition

An oncolytic virus derived from the vesicular stomatitis virus (VSV), a single-stranded RNA virus, and containing a genetically modified glycoprotein (GP) and a human CD80 (B7.1) Fc fragment, with potential immunomodulating and antineoplastic activities. Upon administration, oncolytic VSV-GP BI 1821736 preferentially replicates in tumor cells, and induces VSV-mediated cytolytic activity towards the tumor cells. Viral infection also stimulates the immune system to recognize these same tumor cells, leading to immune-mediated killing of both infected and non-infected tumor cells, thereby further killing tumor cells. In addition, BI 1821736 secretes CD80, which targets and binds to CD28, and in the presence of antigenic T-cell receptor (TCR) signaling leads to the co-stimulation of T-cell responses including the activation of naive and memory T cells. This leads to a cytotoxic T-lymphocyte (CTL)-mediated immune response against cancer cells, thereby killing cancer cells.